1. Field of the Invention
The invention relates to a machine for crimping a terminal to an electrical conductor, and more particularly, to a mechanism which enables extremely fine adjustment of the height of a crimped terminal produced in such a machine.
2. Prior Art
Machines are known for crimping a terminal to an electrical conductor such as a wire or cable. Such machines generally employ a ram which is reciprocally movable with respect to a fixed anvil. The ram carries a crimping die which cooperates with the anvil to crimp a terminal therebetween. In a crimping operation, the ram is driven through a working stroke to deform the terminal and tightly engage the conductor within the terminal to form a crimped connection.
The crimp height, i.e., the height or vertical dimension of the terminal after deformation, is a good indicator of quality of the crimped connection. In order to produce a secure and reliable crimped connection, the terminal must be deformed around the conductor until the height of the terminal is below a certain maximum. Terminals and conductors come in a variety of types and sizes, and the maximum is predetermined for many different combinations of terminals and conductors. Based on pullout tests which measure the tension required to separate crimped terminals of various crimp heights from their associated conductors, the maximum crimp height for a particular combination of terminal and conductor can be calculated. Ideal crimp heights are somewhat below the maximum so as to provide a safety factor against pullout while avoiding excessive deformation of the terminal which may in itself destroy the crimped connection and requires greater energy to produce.
A crimping machine which has been set up to produce a certain crimp height may require adjustment after some time in operation. The need for adjustment may be due to wear of components in the machine, non-uniformity of terminals being crimped, or a change in the type or size of the terminal or conductor. Various mechanisms for adjusting crimp height are known. These mechanisms provide either a means to vary the working stroke of the ram or a means to adjust a rest position of the ram with respect to the anvil, thereby adjusting a dimension from the crimping die to the anvil when the ram is at the fullest extent of its working stroke. The known adjustment mechanisms are somewhat coarse, generally being unable to achieve crimp height adjustments in increments smaller than 0.001 inch.
There is a need for a mechanism that provides extremely fine crimp height adjustments and that is easy to set to a desired value.